and then the other tuns which i went into on a number of occasions which go from gaza into egypt. these are the smuggling tunnels basically used to bring in food, bring in gas, livestock, anything else that the gazans need. and also, according to israel, are used to resupply hamas. that is how they get their weapons into gaza within this blockade. certainly was interesting seeing these tunnels. they very basic. the ground is clay and sand, not particularly conducive to these tunnels. a number of collapses. we have seen over the years israel bombing them quite significantly. but they do seem to keep emerging, and egypt trying to cut back on these tunnels. hamas has a number of years in experience in building these tunnels. brooke? >> israel presumably want to go destroy the tunnels to choke off the point in which hamas is using tunnels to smug, to get the weaponry in. maybe perhaps originally coming